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STMicroelectronics SM50T35AY
- Part No.:
- SM50T35AY
- Manufacturer:
- STMicroelectronics
- Category:
- TVS Diodes
- Package:
- DO-214AB, SMC
- Datasheet:
-
SM50T35AY.pdf
- Description:
- AUTOMOTIVE 5000 W, 30 V TVS IN S
- Quantity:
- Payment:
- Shipping:
Inventory:2,500
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Product details
Overview
SM50T35AY from STMicroelectronics is a unidirectional automotive-grade transient voltage suppression (TVS) diode in SMC package, designed for ISO 7637-2 pulse protection in 12 V/24 V vehicle systems. It features a 35 V nominal breakdown voltage (VBR = 33.2–36.8 V), 48.4 V maximum clamping voltage at 103 A (8/20 µs), 5000 W peak pulse power (10/1000 µs), and ≤0.2 µA leakage at 25 °C - enabling robust surge immunity in e-brake control modules and body electronics.
For engineers reviewing the SM50T35AY datasheet, SM50T35AY pinout, SM50T35AY application, or SM50T35AY equivalent, key selection criteria include clamping performance under ISO 7637-2 Pulse 1/2a/3a/3b, junction temperature derating up to 175 °C, low dynamic resistance (43.0 mΩ), and AEC-Q101 qualification for under-hood deployment.
Technical Context
This TVS diode uses planar silicon technology to achieve stable VBR temperature coefficient (αT = 10 × 10−4/°C) and low leakage across −55 °C to +175 °C operating range. Its unidirectional configuration provides forward conduction path during negative transients while blocking reverse current until breakdown.
The device meets stringent automotive ESD immunity per IEC 61000-4-2 (30 kV air/contact), ISO 10605 (30 kV), and load-dump resilience per ISO 7637-2 (Pulse 1: −150 V; Pulse 2a: +112 V; Pulse 3a: −220 V; Pulse 3b: +150 V), with clamping validated at Tj = 25 °C and derated above.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VBR (min/typ/max) | 33.2 V / 35.0 V / 36.8 V - defines precise turn-on threshold for overvoltage clamping in 12 V/24 V battery systems |
| VCL @ 103 A (8/20 µs) | 48.4 V - maximum voltage seen by protected IC during worst-case surge, ensuring downstream logic stays within safe margin |
| IPP (8/20 µs) | 103 A - peak surge current capability supporting high-energy transients like load dump and inductive switching |
| RD | 43.0 mΩ - low dynamic resistance minimizes clamping voltage rise under high di/dt, critical for fast-rising pulses |
| IR @ VRM | ≤0.2 µA at 25 °C - ultra-low leakage preserves signal integrity and reduces standby power loss in always-on circuits |
| Tj max | +175 °C - enables placement near heat sources (e.g., power relays, motor drivers) without thermal derating penalties |
| AEC-Q101 | Qualified - certified for automotive use including temperature cycling, humidity bias, and mechanical shock testing |
Pinout & Package
SM50T35AY is housed in an industry-standard SMC (DO-214AB) surface-mount package with two terminals: Cathode (marked with bar) and Anode. The JEDEC-registered outline ensures compatibility with automated assembly and IPC-7531 footprints.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| Cathode (bar-marked end) | Surge current sink node | Connected to protected line (e.g., CAN_H, LIN, sensor supply); conducts during positive transients to ground |
| Anode | Reference/ground return | Typically tied to chassis or system ground; completes clamping path during overvoltage events |
Key Features
| Feature | Design Value |
|---|---|
| Planar silicon construction | Enables stable VBR drift (<100 ppm/°C) and long-term reliability under thermal cycling in engine bay environments |
| Low dynamic resistance (43.0 mΩ) | Reduces clamping overshoot during fast 8/20 µs surges, protecting sensitive MCU I/O and transceivers |
| Matte tin lead finish | Ensures solderability compliance with J-STD-002 and whisker resistance per JESD201 Class 2 for high-reliability automotive PCBs |
| ISO 7637-2 Pulse 1/2a/3a/3b compliance | Validated clamping response for all major automotive transient waveforms, eliminating need for external filtering in many designs |
| IEC 61000-4-2 Level 4+ ESD immunity | Withstands 30 kV contact/air discharge - exceeds automotive infotainment and ADAS interface requirements |
Applications
| Electronic Brake Control Module | Body Control Module (BCM) |
|---|---|
|
Use Scenario: Protecting solenoid driver outputs and CAN transceiver lines from inductive kickback and battery reversal during brake actuation. IC Role / Device Role / Timing Role: Unidirectional TVS placed between 12 V supply rail and ground, clamping transients within 1 ns to prevent latch-up in gate drivers. Use Value: Prevents false triggering of ABS actuators by limiting voltage excursion to ≤48.4 V during ISO 7637-2 Pulse 1 (−150 V) events. |
Use Scenario: Safeguarding LIN bus transceivers and door lock actuator drivers against ESD and load dump in centralized body electronics. IC Role / Device Role / Timing Role: Standoff protection on 12 V input rails feeding microcontroller power domains and peripheral drivers. Use Value: Maintains <0.2 µA leakage at 25 °C to avoid parasitic drain on always-on battery circuits while surviving 30 kV ESD per ISO 10605. |
| Engine Control Unit (ECU) Sensor Interface | Advanced Driver Assistance Systems (ADAS) Camera Power Rail |
|
Use Scenario: Shielding analog sensor inputs (e.g., MAP, O2 sensors) from alternator ripple and ignition noise in harsh under-hood environments. IC Role / Device Role / Timing Role: Low-capacitance unidirectional clamp on 5 V reference and signal lines, minimizing signal distortion. Use Value: Delivers 43.0 mΩ dynamic resistance to suppress 100 A surges without exceeding 48.4 V clamping, preserving ADC accuracy. |
Use Scenario: Securing 12 V camera module power input against load dump and hot-swap transients in rear-view and surround-view systems. IC Role / Device Role / Timing Role: Primary surge suppressor upstream of DC-DC converters, rated for continuous 175 °C junction operation. Use Value: Supports 5000 W (10/1000 µs) peak power dissipation without degradation, enabling single-device protection instead of stacked TVS arrays. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar unidirectional TVS diode applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| SMAJ33A | Lower peak power (400 W), higher VCL (53.3 V @ 75.8 A), non-AEC-Q101 | Limited to non-automotive industrial use; insufficient for ISO 7637-2 Pulse 1/3a validation | Select only for cost-sensitive consumer-grade 12 V systems where AEC-Q101 and 5000 W rating are not required. |
| TPSMD33A | Same VBR range but lower IPP (92 A), higher RD (52 mΩ), AEC-Q101 qualified | Adequate for BCM/LIN protection but marginal for e-brake solenoid drivers requiring >100 A surge handling | Prefer when footprint compatibility with SMAJ series is needed and clamping voltage margin allows ≤53 V. |
Compared with SMAJ33A and TPSMD33A, SM50T35AY delivers superior surge robustness (103 A vs. ≤92 A), tighter clamping (48.4 V vs. ≥53 V), and verified ISO 7637-2 compliance - making it the only choice for safety-critical automotive power rail protection demanding AEC-Q101 and 5000 W capability.
Availability
SM50T35AY is available at Aetrix Electronics and suitable for electronic brake control modules, body control units, engine control unit sensor interfaces, and ADAS camera power rails requiring stable component supply across automotive production lifecycles.
Supply support for SM50T35AY includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, specializing in automotive, industrial, and power management solutions with vertical manufacturing and design expertise.
SM50T35AY belongs to the SM50TY series - a family of AEC-Q101-qualified 5000 W TVS diodes engineered specifically for ISO 7637-2 and ISO 16750-compliant automotive surge protection in high-temperature under-hood and chassis-mounted applications.
FAQ
What is the maximum clamping voltage of SM50T35AY under an 8/20 µs surge?
The maximum clamping voltage (VCL) of SM50T35AY is 48.4 V at 103 A for an 8/20 µs waveform, measured at Tj = 25 °C. This value increases with junction temperature per αT = 10 × 10−4/°C, reaching ~52.1 V at Tj = 125 °C using the formula VCL(Tj) = VCL(25 °C) × [1 + αT × (Tj − 25)].
Is SM50T35AY suitable for bidirectional signal line protection?
No - SM50T35AY is a unidirectional TVS diode, intended for DC power rail protection where polarity is fixed (e.g., 12 V supply to ground). For bidirectional data lines like CAN or LIN, the complementary part SM50T35CAY must be used, which features symmetrical clamping for both polarities.
How does SM50T35AY perform under ISO 7637-2 Pulse 1 (−150 V)?
Under ISO 7637-2 Pulse 1 (−150 V, 50 Ω source impedance), SM50T35AY clamps the line to ≤48.4 V within nanoseconds, limiting energy delivered to downstream circuitry. Its 5000 W rating and low RD ensure no thermal runaway occurs, and its AEC-Q101 qualification confirms robustness across 1000+ cycles at full stress.
What is the recommended PCB footprint for SM50T35AY?
The recommended footprint follows IPC-7531 and JEDEC MO-136 standards: pad length 5.11 mm, pad width 3.14 mm, center-to-center spacing 8.19 mm, with 1.54 mm solder mask clearance. Copper area under each lead should exceed 2.5 cm² to maintain Rth(j-a) ≤ 40 °C/W and support full 5000 W pulse handling without excessive temperature rise.
SM50T35AY Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- DO-214AB, SMC
- Series:
- -
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- Zener
- Unidirectional Channels:
- 1
- Bidirectional Channels:
- -
- Voltage - Reverse Standoff (Typ):
- 30V (Max)
- Voltage - Breakdown (Min):
- 33.2V
- Voltage - Clamping (Max) @ Ipp:
- 48.4V
- Current - Peak Pulse (10/1000µs):
- 103A
- Power - Peak Pulse:
- 5000W (5kW)
- Power Line Protection:
- No
- Applications:
- -
- Capacitance @ Frequency:
- -
- Operating Temperature:
- -55°C ~ 175°C (TJ)
- Grade:
- Automotive
- Qualification:
- AEC-Q101
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- SMC
SM50T35AY FAQ
1.How can I place an order for SM50T35AY through Aetrix?
Please submit a Request for Quotation (RFQ) for SM50T35AY on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SM50T35AY reliable?
The price and inventory of SM50T35AY are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SM50T35AY is usually 5 days.
3.What payment methods are accepted for SM50T35AY?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SM50T35AY transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SM50T35AY?
SM50T35AY orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SM50T35AY order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SM50T35AY?
For technical support, including SM50T35AY datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SM50T35AY requirements.
6.How does Aetrix verify that SM50T35AY is sourced from the original manufacturer or authorized distributors?
All SM50T35AY products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SM50T35AY meets industry standards.
7.What is the process for return or replacement of SM50T35AY?
All SM50T35AY units undergo pre-shipment inspection (PSI). If there is an issue with SM50T35AY, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SM50T35AY part is unused and in its original packaging.
Return procedure for SM50T35AY:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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